Field of the Invention
The present invention relates to an electrophotographic member to be used in an electrophotographic apparatus, and a process cartridge and an electrophotographic apparatus each including the electrophotographic member.
Description of the Related Art
In an electrophotographic image forming apparatus (such as a copying machine, facsimile, or printer employing an electrophotographic system), an electrophotographic photosensitive member (hereinafter sometimes referred to as “photosensitive member”) is charged by a charging unit and exposed by a laser or the like, and as a result, an electrostatic latent image is formed on the photosensitive member. Next, toner in a developer container is applied onto a toner carrier by a toner-supplying roller and a toner layer thickness-regulating member. The electrostatic latent image on the photosensitive member is developed with the toner conveyed to a developing region by the toner carrier at a portion in which the photosensitive member and the toner carrier are in contact with, or close to, each other. After that, the toner on the photosensitive member is transferred onto recording paper by a transfer unit, and is fixed by heat and pressure. The toner remaining on the photosensitive member is removed by a cleaning blade.
In the electrophotographic image forming apparatus, an electrophotographic member including an electroconductive base material and an electroconductive resin layer on the base material is used as a member such as the toner carrier, a charging member, the toner-supplying roller, the cleaning blade, or the toner layer thickness-regulating member. In some cases, the electroconductive resin layer in such electrophotographic member has added thereto an ionic electroconductive agent, such as a quaternary ammonium salt compound, in order to control its electrical resistance value to from 105Ω to 109Ω.
However, the electrical resistance value of the electroconductive resin layer having electroconductivity imparted thereto by the ionic electroconductive agent is liable to fluctuate depending on its surrounding environment. Specifically, its electrical resistance value under a normal-temperature environment having, for example, a temperature of 23° C., and its electrical resistance value under a low-temperature and low-humidity environment having, for example, a temperature of 0° C. significantly differ from each other in some cases.
As a measure against such problem, in Japanese Patent No. 4392745, there is a disclosure of a method involving using an ionic liquid having a specific chemical structure for a rubber composition. In addition, in Japanese Patent Application Laid-Open No. 2011-118113, there is a disclosure of a method involving using an ionic liquid having a hydroxy group in a urethane resin composition.